Motor driven hack saw



Aug. 20, 1935. J, P. FRENCH MOTOR DRIVEN HACK SAW Filed April 30, 1932 2Sheets-Sheet 1 WY m .0 mm m NW mm m 5 M M w% w 6 m 2 Aug. 20, 1935. J.P. FRENCH MOTOR DRIVEN HACK SAW Filed April 30, 1932 2 Sheets-Sheet 2INVENTOR. db/m gF/ww ATTORNEY.

Patented Aug. 20, 1935 MOTOR DRIVEN HACK SAW John il French, Alma,Mich., assignor of one-half to Frank E. French, Jr., Alma, Mich. Frank0. Parker. administrator of saidJohn 1?. French,

' deceased Application April 30, 1932,8erial No. 608,388

6 Claims.

The object of the invention, generally stated, is to provide a hack sawconstruction having an improved holder which permits a slightyielding ofthe saw blade in a direction-opposite to the direction of feed inorderto cushionthe blade during the first part of the cutting stroke.

The above and-other objects will-appear as the specification progresses,reference being had to the accompanying drawings, in which I have shownthe preferred embodiment of my invention,

and in which like referenoenumerals indicate like parts throughout theseveral views thereof. In the drawings Fig. 1 is a side view of myimproved hack saw,

showing the saw blade holder and the pivotal connectionsfor theends'ofthe saw blade.

Fig. 1 is a sectional view'taken substantially along line E I of Fig. 1and is on a slightly larger'scale.

Fig. 2 is a part sectional top plan view taken on the-line 2-2 of Fig.1;i

Fig. 3 is an enlarged sectional end view taken on the line 3-3 ofFig.1.I

Fig. 4' is a part sectional end View taken on the line i 3 of Fig. 1. Y

Fig. 5 is an enlarged'part sectional fragmentary front view,illustrating the saw frame raising means, the dotted lines-showing-it inraised position. r

Fig. 6 is a top plan viewthereof.

Fig. 7 is an enlarged detail of the chain link connection. 1

Fig. 8 is a front view of the chain yoke.

' Fig. 9 is an end view thereof. I

Fig. 10 is an enlarged sectional view of the feed screw pilot andbearing.

ings, the device comprises a base 5 having a socket 5 castintegral-therewith and in whicha standard I is inserted, said standardsupporting the main frame and is rotatable to permit the work to be cutat an angle when necessary; a set screw 8 serves to hold the standard insetposition, and one side wall 9 of said socket is flat and forms thesta-' tionary jaw of the vise'inwhich the work Bjxis clamped. 7 Q

The base is preferably cast,ho1low as clearly shown in Figs. 1 and 4 ofthe vdrawingsaslot being formed in the face thereof, and a similar slotI i is provided in the lower wall, a boss I 2 being cast-integral withthe one end, and isinternally bored and threaded to receive the threadedadjusting rod l3 which is'mounted therein, a handle i4 being-pivotallyconnected to the outer end of said rod to facilitate manipulationthereof.

A flat-faced jaw' i5 is ,pivotally secured to the opposite end of therod 13, and is mounted to openings in said rib, ber in-position, boltsthe slot H, and serve bench or other support.

A preferably tubular guide or track member. is is secured to thestandard 1 by means of sup-' porting arms 23, said arms being rigidlysecured to the standard and the like.

A sleeve member 22 is slidably mounted on the post'l, and a channelshaped laterally projecting frame section 23 is cast integral therewith,an olfset -leg 24 being cast integral with the sleeve, the outer endbeing'bored to accommodate the guide is, said leg beingsplit as shown at25, and a bolt 26 serves to clamp the ends together permitting the legto freely slide on the guide.-

A laterally projecting lug 21 is cast integral with the upper supportingarm 26, and an opening 28 is provided therein adapted to provideafriction bearing for the frusto conical projection of a pilot member29. .The upper end of a feed screw 30 is fixedly securedin the lowerpart of the pilot member and a handle 3! is formed integral with theupper end of the pilot member to rotate the latter and the screw 30 whendesired. An internally threaded bushing 32 ismounted in the frame asshown, and a ratchet wheel 34 is fixedly secured thereon. A pawl-lever33 is rotatably mounted on the lower end of the bushing, and a pawl 35is pivotally mountedon said lever in position to engage the ratchetwheel 35, a spring member 36 being anchored to said lever and to asuitable brace 3'i-providedon the sleeve 22, shown in Figs. 1, 2 and16of the drawings, so that as the lever is actuated the pawl 35 inengagement with the ratchet wheel, will rotate the ratchet wheel and thebushing 32 to cause the same to ride downwardly on the screw 30. By.holding the ratchet wheel .34 stationary w 'le rotating the screw 38.clockwise by means of handle 3i, the ratchet. wheel and thebushing maybe returned toward the upper part of the screw.

Spaced apart hubs 38am cast integral with the'frame and are bored toformbearings in which'the shaft 39 and 49 are journaled, the shaft 39having a sprocket 4| mounted thereon, and a similar sprocket 42 ismounted on the shaft ill, a gear ZS 'being mounted on the opposite endof said shaft, meshing with and being driven by a gear 44, which is inturn mounted on the driving motor 45 in anyapproved manner, the gears 43and Mbeinginclosed ina grease-tight gear box 46, so that the operationwill be smooth and noiseless, and a back plate 37 is cast integral withthe motor and forms aclosure for the back of said gear box.

Guides ifiaresecured to the upper andlower side walls, of the frame 23by means of screws 49, and away is,provided in each guide and is guideby means of pins 2! or adapted to accommodate spaced. apart horizon- 3 atr sh cu -v Rollers 5G and-'51 are interposed between the member'BQ,rocking iton the pin 6!, and as in-, dicated in dotted lines in.

.sawframe is raised to positionshown in dotted The frame isthenjreturned to the leftand remains in raised position,

1 ventional tension block 54 by'jthe friction bearing tally dispbsedbars 5 If, a which formthe 'upperfpart ofthe saw frame proper. The ends'ofthje bars 5t are secured to end,members 52 and 53,13 spectively,

which areU-shaped in cross SGCtiOIflz.

sary friction to hold the member 59in raised position during 'thelreturnstroke; 4 M

sWhatI claim is: f

1. A saw-blade holder comprising, in combinat'on, a carrier frame, asaw-blade, means for se- A blade 54 is connected between the-lowerendsof the saw frame and is held at its rear'en'dby-a conmounted in; a"suitably ap ertured portion at the lowerend ofthe-member I 52. The frontend of the blade is pivotally'con- .nectedto a compensating link 55,which may be in the form of a suitably shapedblock mounted in theapertured lower end of the sawframe member 53and pivotally'connectedthereto; When the saw is fed into thework, the link 55'pivots to p r ter rq t e of t e d t sp i upwardly, andrasthesawadvances on the cuttingstroke, the link gradually drops back to its normal I, I position.This;springingaction of the blade produc'es' a 1 cushioning area which,preventsthe blade from twisting and chattering and insures bar members5I,=the roller 56 being mountedon a suitablepin whichis in turn mountedin the.

hub 58' which forms a part of the main frame, the oppositerolleril beingmounted on'an angularly disposedfmember 159, said member being pivotally mounted on a rib 60, (which is cast integralwith th lframe) bymeans of the, pintl,

said rollersbeing so; disposed thatthe frame free lyrolls thereon;

A suitable sprocket chain connectsthe sprockets 4i and 42 and a drivingpin 63 is'pro- ,videdintei rnediate the length of said chain, andengages a slotted opening 64 provided in the yoke 65, which' is in turnsecurely riveted to the bars 5!,- andit will be clearthat as the. chaintravels the drivingfpin which :engages the yoke 65 will reciprocate thesaw frame accordingly.

."Ihe lu shaped member 53- which forms the front end 'I'of the saw-frameprojects above the bars'E l', andaslottedc ntact bar 661s adjustablymounted'thereon by mean's of screws 61, and as the'saw frame isreciprocated, the ,end of the bar 1 the sawffeed maybe regulated asdesired; and the'spring member. fifi forces the lever 3 3 back tooriginal position.

In, the operation stroke whichis toward the rightas seen in Fig. '1

anda pin 68 is, therefore, provided on theuppe'r 7 bar 5!, saidpinengaging the upperl'eg 69 of the igl 5, and so that the lines of thesamefigure.

., until'it has r-eached the' extreme' end of the re:

turn stroke, when the pin 19", which is -mounted adjacent'the end of thebars 5I,"engage sthe cp s me s d o th l e fiaswingina h c I original'positiomand the sawthenfeedsinto' the a work on; the cuttingstroke; 12.v spring washer 1 l V is mounted on the pint] andp'rovides the'necesofithe devises is e sential 60 that thesaw be, raisedron thelend. of thecutting,

cnring-theffront end of the blade to the frame permittingthe front endof the blade to spring slightly in theplane'of the blade during acutting stroke, and means for securing the rear end of the'blade'to'the; frame against movement relative thereto'otherithan pivotalmovement and ifor adjusting th''tension of the blade.

12. A. saw blade holder comprising, in combination, a reciprocatoryframe, a saw'blade, and a pair of blocks,- f or attaching the respectiveends of the fbladetol the frame withethe cutting edge of the bladenormally parallel to the direction of reciprocation .-and placing theblade under tension lengthwise; thereof, the block 'at the front end oftheblade having agslight pivotal movement relat ve. to. the frame andtothe blade as anjin- ,ci dentjo'f:the pressure of the blade,. againstapiece of work to; decrease the-depthpfcutduring the first-part ofthecutting stroke and to increase the t n o i evlb ad V A'saw-bladeholdercomprising, in coinbinae tion, a U-shaped frame having aperturesin the ends of the respectivelegs of the frame, a saw blade, a membersecured to the rear end of said blade against; movement relativetheretoother than pivotal movement and secured rigidly in theaperture-brone of the le iof the, frame for adjustment longitudinally ofthe blade totighten theblade, anda block pivotally-secured to the frontend of the blade and pivotally secured in the aperture in theother leg,of the frame on an axis transverse to the bladeto permit the front endof the bladetospring. during a; cutting stroke in the direction oppositeto thedirection of feed.

4. A saw-blade holderfor hack saw-machines comprising, in; combination,a, carrier, and means for mounting the ends of afl-blade in the carrierandoperable to place the blade under a normal predetermined tensionlengthwise thereof, 7 said ineanshaving :a slight pivotal movement atthe forward endof the blade in a direction to in crease thej -tensionofthe blade and caused as an incident of the pressure of the bladeagainst a n w rk- V 1 r I 5.In"a device of the character described,including a' base, a'standard mounted thereon, a main framejslidably andadj ustably mounted on saidstandard, a saw frame reciprocably mounted onsaid ma nframeand including a pair of saw holding arms, a,;memberrigidly held in one of said arms and" providing a fixed pivotal connection amneendor the saw, and a member piv;

otallyconnected to the other saw frame arm and pivotally connected tothe end of the saw to per- -mit bne" end "of the saw blade to spring inthe plane of the blade during the cutting stroke.

6. The combination with a power driven hack saw, ofQa supporting frame,a saw frame re-- ciprocably'carried by said'supportingframe, powerdrivenmeans for reciprocating saidframe', a saw blade, means for securing thefrontend of theblade'to the, saw frame permittingthe-front end" of theblade to spring slightlyin the planeof the, blade during abuttingstroke,-. and means for se'culiingthe rea'r end. of 'theblade to theframe against movementjrelative thereto other than pivotal movement andfor adjusting the tension o-ftheblade 1 f 1.103? was;

